Continuous casting apparatus



July 2l, 1959 FiledJune 4, 1956 A. WITTMOSER CONTINUOUS CASTINGAPPARATUS 4 sheets-sheet 1 INVENTOR. WMM-Mmmm www. s. Am/W July 2l, 19594 A, W|TTMQ5ER 2,895,188

v CONTINUOUS CASTING APPARATUS Filed June 4, 1956 4 sheets-sheet 2INVENTOR.

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' Filed June 4, 1956 CONTINUOUS CASTING APPARATUS 4 sheets-sheet 4INVENTOR.

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2,895,188 Patented July 21, 1559 United States arent Oilice CONTINUOUSCASTING APPARATUS AdalbertV Gelsenkirchen, Germany, assigner Y to FirmaEisenwerke yGelsenkirchen Aktiengesellschaft, Gelsenkirchen,l GermanyThe present invention relates to apparatus for continuous casting ofmaterials, and this application is alcontinuation-in-part of co-pendingapplications Serial No. 405,- 425, filed January 21, 1954, nowabandoned, and Serial No. 517,811, led June 24, 1955, now Patent No.2,762,096, dated September 11, 1956.

Morev particularly, the -invention relates to a casting apparatus`including a continuous casting mold `and a discharge vessel fordischarging molten metal in aV controlled manner into the continuouscasting mold.

The present apparatus provides for the delivery of molten metal or othercasting material into a casting mold for forming products` having eitherasolid or a hollow cross section, the present device being of the typewherein a movable discharge vessel containing the casting material isarranged for discharging the casting material into the mold as the levelof the casting material in the continuous casting mold drops. t

Such types of movable discharge vessels, which may be moved for changingthe same in a desired position over the surface of the metal `or othermaterial in the mold, are of particular advantage in the manufacture ofhollow bodies such as tubes, pipes and the like, andv of products havinga solid cross section of which the cross section in one direction isrelatively narrow and in the otherdirection is relatively long. Anadvantage of the present apparatus residesiin vthe fact that lonly a fewoutlet openings are necessary. in the discharge vessel in spite of'largesurface areas of the metal in the mold device. In this way there ismade possible a uniform and rapid distribution of the outflowing metalover the entire metal surface in the interior of the mold.

In known devices of the above type, a discharge vessel Vmay beprovidedwith individual discharge openings extendingthrough the bottomthereof. These channels or Vnozzles are formed with fixed passagecross-sections and 'are arranged verticallyt'or inclined in positionover the mold cavity or over the walls of the outer mold member vor ofthe core thereof. The amount of molten metal therefore depends upon theparticular cross-section of the dscharge openings, and a variation inthe amount of the delivered molten` metal is produced by a correspondingdegree of tilting vof the delivery conduit which supplies the moltenmetal to the discharge vessel. In this way a greater or lesser amountofthe molten metal ows into the discharge vessel from the supply-vessel,`By raising -the 'level vof the metal in the discharge vessel, the pres-`sure of the molten metal isincre'ased, which causes an `increase in therate offlow of the molten metal through ,the discharge openings.

in spiteof the increase in the speed of ow of the molten metal throughthev outlets due to the increased staticpressure of the metal, thedesired variation in the amount of molten metal discharged cannot becarried out with suliicient rapidity as is necessary and desirable inorder to maintain a constant level of the casting material in the mold.

It is, therefore, an object of the present invention to overcome theabove disadvantages in continuous casting devices of the above-mentionedtype.

It is another object of the present invention to provide a continuouscasting apparatus wherein the level of the casting material in the moldmay be kept relatively constant.

It is still another object of the present invention to provide adischarge vessel for use in a continuous casting apparatus which allowsfor rapid changes in the rate of discharge of the casting materialtherein into the continuous casting mold inaccordance with variations inthe rate of delivery of the molten material t-o the discharge vessel.

It is still a further object of the present invention to provide adischarge vessel of the above type wherein foreign substances may bekept from iiowing with the casting material from the discharge vesselinto the casting mold.

The objects of the present invention also include the provision of acasting apparatus capable of uniformly supplying molten metal to thecasting mold.

It is yet another object of the present invention to provide acontinuous casting apparatus which is so constructed as to enable theoperator to observe the pouring of the molten material, particularly theplace at which the stream of molten metal impinges upon the liquid metalalready in the mold. j

Other objects and advantages will become apparent from the lfollowingdescription and the appended claims.

With the above objects in View, the present invention relates to adischarge control device for use in a continuous casting apparatus whichcomprises a device for controlling the discharge of casting materialinto a continuous casting mold, comprising a vessel having an inlet atits top and having a side Wall, the vessel being formed in the sidewall, with at least one elongated outlet extending substantially axiallyof the vessel, whereby the rate of discharge of the casting materialfrom the vessel through the elongated outlet may be rapidly varied inaccordance with the rate of delivery of casting kmaterial to the vesselthrough the inlet thereof.

According to a preferred embodiment of the present invention mold meansare provided which define an upwardly extending annular space adapted toreceive molten metal, and moltenv metal supply means are arranged abovethe mold means and are at least partly within an upward annularextension of this annular space. That part of the supply means which isin the upward annular extension is formed with outlet means throughwhich molten metal received by the supply means may tiow into theannular space The novel features which are considered as characteristicfor the invention are set forth in particular in the appended claims.The invention itself, however, both as to its construction and itsmethod'of operation, together with additional objects and advantagesthereof,

vwill bev best understood from the following'description 'of specicembodiments when read Vin connection with :slots 21.

Fig. 3 is a fragmentary view partly in section of an embodiment of thepresent invention;

Fig. 4 is a fragmentary plan view of the discharge vessel shown in Fig.3;

Fig. 5 is a fragmentary View in section vof another embodiment of adischarge vessel constructed in accordance with the invention;

Fig. 6 is a view of the device shown in Fig. 5 taken in the direction ofthe arrow shown in Fig. 5; v

Fig. 7 is a plan view of a portion of a discharge vessel constructed inaccordance with the invention incorporating a trap device;

Fig. 8 is a View 4of the device shown in Fig. 7 taken along the lineVIII-VIII; and

Figs. 9 to 11 are fragmentary plan views, respectively, of threeembodiments of a supply vessel according to the present invention.

Referring now to the drawings, and particularly to Fig. l, there isshown a continuous casting apparatus which includes a separablecontinuous mold device 10 having a lower outer mold member 11 and anupper outer mold member 12, and having upper and lower core members 13and 14, the mold members being arranged to to provide a mold cavity 15therebetween in which a metal pipe, for example, may be continuouslycast. In the casting apparatus shown in Fig. l a -mold for making socketpipe is shown, the mold being so arranged that a socket cavity 16 isdefined at the lower portion thereof for making the socket portion of asocket pipe. In the operation of the particular mold for continuouslyforming cast pipe as illustrated, the lower portion of the mold isgradually lowered in a direction away yfrom the upper mold portions asthe shaft of the formed pipe solidies, thereby lowering the level 17 ofthe molten metal at the top of the mold cavity 15. As the level 17 ofthe molten metal drops, additional molten metal is discharged from theoutlets of the discharge vessel 18, as more fully described herein. Itis to be understood that the maintenance of level 17 at a constantheight can be continuously carried out by the continuous discharge ofmolten metal from discharge vessel 18 as the level 17 drops.

The `supply of molten metal to discharge vessel 18 may be carried out inany suitable manner, the means illustrated being a supply vessel 19which is movably supported above a conduit 22 from which the moltenmetal flows into the discharge vessel 18. The supply vessel 19 istiltable about a horizontal axis so that a greater or lesser amount ofmolten 'metal may be delivered to the conduit 22 and consequently to thedischarge vessel 18 as desired.

ADischarge vessel 18 may itself be movably mounted above the castingmold 10, and may, if desired, bemade l rotatable about its axis, so thatthe discharge outlets there- 1n may be arranged above any desiredportion of the open top of the mold cavity 15.

Discharge vessel 18 Imay be provided with one or more discharge openingsof the type hereinafter more fully described and shown in the drawings,and the vessel may be either of annular form as shown in the drawings,or it may be merely of cup-shaped form of any desired peripheral shape.It is necessary only that the shape of discharge vessel 18 be such thatthe discharge openings thereof are properly arranged above thecontinuous casting mold 10 to provide for discharge of the molten metalinto the mold cavity 15.

Fig. 2 is a plan view of one form of a discharge vessel which is ofannular shape and is 'provided at spaced intervals around its peripherywith elongated outlet slots 21, the discharge vessel 20 being formedwith a central conical wall which defines between itself and the outerwall a trough 23 in which the molten metal may be poured from the supplyvessel by a forked conduit 22, and from which the molten metal isdischarged through The number and arrangement of the slots 21 may 'bevaried as desired, and, in fact, only a single slot may be provided, inwhich case the discharge of molten metal therethrough in a uniformmanner into the mold cavity of the type shown in Fig. 1 may beaccomplished by rotating the discharge vessel about its axis by anysuitable means.

The arrangement of the discharge vessel with respect to the continuousmold is shown in greater detail in Fig. 3. As shown in Fig. 3, thedischarge vessel 4 which is of annular form is so arranged that themolten metal 24 contained therein is discharged through slot 5 directlyinto the Imold cavity 3, which is defined between the outer mold member1 and the core mold member 2. The discharge slots 5 are formedpreferably in circumferentially spaced arrangement in the outer wall 25of discharge vessel 4. Slots 5 may have uniform width along theirlengths, or they may be of increasing width as they extend upwardlytoward the top of outer wall 25. Preferably, slots 5 extend all the wayto the top of outer wall 25 so that they are open at their top ends. Thelower ends of slots 5 are preferably spaced above the bottom 6 of thedischarge vessel 4, in order to provide for a continuous ring of moltenmetal at the bottom of the discharge vessel 4.

Fig. 4 shows a plan view of the device shown in Fig. 3, the curvedformation of the discharge vessel walls and the trough formed thereby aswell as the top of slot 5, being more clearly illustrated therein.

The embodiment of the discharge vessel 4a shown in Figs. 5 and 6 differsessentially from that shown in Figs. 3 and 4 in that the lower portion5a of the outlet slots 5 have a particular width for the casting of atubular cast article, while the upper portion 5b of the slots is widenedin a stepwise manner in order to provide for the casting of a socketportion of the tubular article. Such socket casting is carried out atthe beginning of the casting operation by raising the level of themolten material in the discharge vessel 4a above the stepped portion `ofthe slots, so that a relatively greater amount of molten material may beinitially discharged into the casting mold for forming the relativelylarger volume of the socket portion of the pipe.

In the embodiment shown in Figs. 7 and 8, the annular discharge vessel4b is provided with a slag catching member or trap 7 which is arrangedadjacent each slot 5c in the manner shown in Fig. 8, the slag catchingmember 7 being preferably of a domed or roof-shaped form, the,arrangement of member 7 in the vessel 4b being such that foreignsubstances such as slag particles are prevented thereby from passingthrough the discharge slots 5c into the molding device.

The device constructed in accordance with the invention operates in suchmanner that when the surface of the molten metal drops a substantialamount in the continuous casting mold 10, the level of the molten metalin the discharge vessel 18, as shown in Fig. 1, is increased by addingadditional molten metal thereto, and in this way the molten met-altherein flows out of the lateral outlet slots 5, such as shown in Fig.3, without any delay, so that a greater amount of molten metal isdischarged into the continuous casting mold 10. As a consequence, thelevel of the molten metal in the casting mold is quite rapidly broughtagain to the desired or necessary height.

By virtue of the arrangement shown in the embodiment of Figs. 5 and 6,it is possible to control the relative amounts of the molten metaldischarged through the outlet slots 5 where at one time a comparativelyrapid discharge i's required While at another time `a substantiallyslower discharge is desired, as, for example, in the casting of socketpipes. In this way, as pointed out above, in the casting of the socketportion of the pipea relatively great amount of ymolten metal may beinitial-ly discharged into the casting mold, while thereafter in castingthe shaft portion of the socket pipe which adjoins the socket portion, asmaller amount of casting materialper unit of time may be discharged.

This process is achieved by initially providing a comparatively Ihighlevel of molten metal in the discharge vessel 4a (Fig. 5), so that thelthe level of the casting material therein is so high that the castingmaterial ows not only through the lower portion 5a of the outlet slotswhich are of normal width, but also through the widened upper portion 5blof the slots 5. Shortly before the end of the process of casting of thesocket portion, or duringthe casting of the transition portion betweenthe socket and shaft portions of the pipe, a lesser amount of castingmaterial is delivered to the discharge vessel 4a, so that the level ofthe molten material therein drops below the vwidened portion 5b of theoutlet slots 5 therein. The delivery of the molten material at thereduced rate is then substantially maintained in casting the shaftportion of the pipe.

In similar manner,other hollow articles having other types of lVariablecross section may be cast.

In order to provide for uniform distribution of the molten metaldelivered to the discharge vessel, 4, the bottom of the discharge vesselis preferably made deeper than the lower end of the slots 5 in the sidewall, as Ishown inFig. 3. In this way a continuous ring of moltencasting material is provided in the bottom of the discharge kvessel sothat all of the discharge Slots 5 discharge molten materialsimultaneously as soon as the level of the molten material reaches theVbottoms of the slots 5 which are arranged at the same level.

By virtue of the trapping device shown in the embodiment illustrated inFigs. 7 and 8, the trapping of foreign substances such as slag particlesby the trap 7 prevents the foreign substances from flowing into thecasting mold,` Iand this feature provides for maintenance of a higherquality of the products cast in the casting mold.

Figs. 9 to ll are fragmentary plan views, respectively, of threeembodiments of a supply vessel according to the present invention.

In the embodiment shown in Fig. 9, the supply vessel, which may bemounted for rotation relative to the mold in the direction of the arrow,has an annular portion 101 and a transverse portion 105 which projectsinto an upward annular extens-ion of the annular mold chamber 102 whichis the annular space formed between outer and inner mold walls 103 and104. The transverse portion has a side wall which is formed with atleast one substantially vertical slot 106 through which molten metalreceived by the vessel may ow into the mold chamber 102. The slot mayhave any suitable configuration, as, for example, any one of thecongurations shown in the previously described embodiments wherein thewidth of the slot increases from the bottom toward the top of thevessel. Also, a trap member 113 may be arranged in the vessel at thejuncture of the annular and transverse vessel portions 101 and 105 forpreventing the entry of slag or other foreign substances in the moltenmetal into the transverse portion 105, thus preventing the discharge ofsuch foreign substances through the slot.

In this way, the stream of -metal issuing from the slot may be caused toimpinge upon the liquid already in the mold chamber at a place spacedfrom the inner and outer mold walls, particularly if the mold chamber isof such Width that if the molten metal were to issue from an openingformed in the annular vessel portion instead of the transverse vesselportion, such stream would impinge upon the metal already in the moldchamber at point relatively near the inner mold wall 104.

While the embodiment shown in Fig. 9 is one wherein the annular vesselportion is encompassed by the upward annular extension of the moldchamber, the transverse vessel portion thus being an outwardly extendingone, it will be understood that the annular vessel portion may encompassthis upward annular extension, in

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which case the transverse vessel portion would be an inwardly extendingone. The provision of the outlet slot in such inwardly projectingtransverse portion would thus enable the stream of molten metal toimpinge upon the metal already in the mold chamber at a point spacedfrom the outer mold wall 103.

It has been found that although the transverse portion projects over themold chamber, it is still a very simple matter for the operator toobserve the surface of the molten metal within the mold chamber, evenwhere the supply vessel is provided with two, three, four or moretransverse portions, particularly when the supply vessel is rotatedrelative to 4the mold means.

Another embodiment of a supply vessel according to the present inventionis shown in Fig. l0 wherein parts 101a, 102a, 103a, 104a, 105a and 11341correspond, respectively, to parts 101, 102, 103, 104, and 113 of theabove described embodiment. The instant supply vessel however differsfrom the one shown in Fig. 9 in that the transverse portion 105a isformed with two side walls facing the outer and inner mold walls 103aand 104g, respectively. Each of these side walls is formed with anoutlet 'slot 107, 108 so that molten metal may issue therethrough intothe mold chamber 102a'.

In the embodiment shown in Fig. ll, wherein parts 101k, 10212, 103]),10417, 10511 and 113b correspond, respectively, to parts 101, 102, 103,104, 105 and 113 of the embodiment shown in Fig. 9, the outlet slots areangularly displaced relative to each other. However, in this embodiment,as in the one shown in Fig. l0, one of the slots is in a side of thetransverse portion which faces an upwardly extending cylindricalprojection of the inner wall 10415 of the mold, and the other slot is ina side wall of the transverse portion which faces an upwardly 'extending cylindrical projection of the outer wall 103]: of the mold. lfdesired, a dellector or baffle plate 111, 112 may be provided for eachslot for preventing the stream of molten metal issuing from each slotfrom impinging upon the walls of the mold before dropping into the moldchamber 10211.

The present invention provides several distinct advantages, as follows:

There is assured, by virtue of the invention, an immediate properproportioning of the amount of molten metal discharged into the moldcavity, in accordance with a greater or lesser tilting of the supplyvessel or conduit which delivers the molten metal to the dischargevessel, and this result can be achieved as well in the continuouscasting of workpieces which have uniform cross sections, as well as inthe continuous casting of workpieces which have markedly different crosssections, as, for example, socket pipes. Further, the manufacture of thedischarge vessel is considerably simplified, since in accordance withthe invention the outlet slots may be easily formed in the side wall ofthe discharge vessel so as to have the proper cross-section, in contrastto the known arrangements wherein discharge openings are provided in thebottom of a discharge vessel, the discharge openings of these devicesbeing made of a particular calibrated cross-section to provide for aparticular speed of casting.

Furthermore, there is provided in accordance with the invention greaterease of cleaning of the discharge vessel, with consequent greaterdurability of the vessel, because the removal of the residue of themolten material after the casting process can be carried out much moreeasily and thoroughly than in the case of discharge nozzles or openingsof small cross-section as provided in the prior art devices.

Also, the influence of the flowing quality of the molten material on thecasting process is reduced, since it is possible in the case, forexample, of thickly flowing molten material to fill the discharge vesselto a higher level and in that way the amount of discharged molten met-alper unit of time may be kept uniform.

Finally, a further advantage resides in the -fact that in the forming ofhollow bodies by means of an annular discharge vessel, only a fewsuiciently large slots suffice for satisfactory discharge of moltenmaterial into the mold.

It will be understood that each of the elements described above, or twoor more together, may also nd a useful application in other types ofliquid discharge devices dilering from the types described above.

While the invention has been illustrated and described as embodied incontinuous casting apparatus for making pipes, it is not intended to belimited to the details shown, since various modifications and structuralchanges may be made without departing in any way from the spirit of thepresent invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a metal casting apparatus for casting tubes or the like, incombination, mold means including concentric cylindrical inner and outerwall means forming between themselves an upwardly extending annularspace adapted to receive molten metal; and a molten metal supply vesselarranged above said mold means, said vessel having an annular portionlocated exteriorly of an upward annular extension of said annular spaceand at least one transverse portion projecting into said upward angularextension, said transverse portion being so constructed and arranged asto have at least two side walls facing au upwardly extending cylindricalprojection of said inner wall means and an upwardly extendingcylindrical projcction of said outer wall means, respectively, each ofsaid side walls being formed with at least one substantially verticalslot through which molten metal received by said vessel may ow into saidannular space so that the rate of discharge of molten metal through saidslots is dependent upon the height of the liquid level within saidvessel, whereby the rate of discharge of molten metal from said vesselthrough said slots may be varied in accordance with the r-ate ofdelivery of molten metal into said vessel. l

2. The combination dened in claim 1, and deector means carried by saidvessel and being arranged 'in the path of a stream of molten metalissuing from each of said 4slots in such a manner that the molten metalimpinges upon said dellector means and thereafter drops into saidangular space.

3. The combination defined in claim 2 wherein said deector means areconstituted by a plurality of deector plates associated with each ofsaid slots, respectively.

References Cited in the file of this patent UNITED STATES PATENTS125,044 Guthrie Mar. 26, 1872 2,224,303 Junghans Dec. 10, 1940 2,659,120Harter et al Nov. 17, 1953 2,757,425 Duncan et al. Aug. 7, 19562,762,096 Wittmoser Sept. 1l, 1956 2,793,410 Junghans et al. May 28,1957 FOREIGN PATENTS 746,211 Germany June 15, 1944 911,065 Germany May10, 1954 1,079,898 France May 26, 1954 1,091,600 France Oct. 27, 1954

